Hi Camille, I don't write poetry, but I hade/have a similar concern regarding dance.
I loved to dance, in order to put my trapped energies in motion and to have access to my repressed emotions, to stop my inner dialogue and connect to another part of myself, to connect to another person in a way other than through words. For me it was a really effective way for that. It led me to explore territories that I couldn't explore otherwise, take a step back from certain situations and broaden my perspective, to open up to people (I was very shy and closed); but at a certain point it wasn't enough for me anymore. I wanted to create dances. But how could I do it? I didn't just want to create nice empty forms, to tell stories, to mime or at best express personal emotions. That's when I came across Gurdjieff's writings on art. Like you, I felt he was right, but somehow it blocked my impetus... I found it 'cold'. Where was personal creativity?
I had tried to solve, at least conceptually, the dilemma by telling myself that the true artist captures essential, abstract truths, the names of gods, and makes them manifest, in a creative way, through symbols, poems, music, dances...
Recently, after reading what Laura and the C's said about dance, I got back to the subject (I have also begun to read what Jeanne de Salzmann says about dance) and I will share my findings with you.
But you can also try to just write and let it flow, as Hello H2O said, and see where it takes you